The growing market for the microbiome
Bacteria in the gut, the phrase can suggest disease-causing agents like Salmonella and Campylobacter, pathogens that churn up our insides and knock us out of action. Like many trouble makers these bugs have a degree of notoriety, but they are not typical gut bacteria. Most of the microbes in our intestines are not out to cause trouble. Research over the last ten years has shown that our gut microbes are actually contributing to our health.
Our relationship with microbes starts at birth. They are passed on during intimate contact between mother and newborn. Bifidobacteria are delivered in breastmilk, which is also a source of oligosaccharides, food for microbes that then set up home in the colon.
By the age of three we have a complete repertoire of at least thirty genera of microbes in our intestines. They each have their favourite places, some nestle close to the gut wall, others sit out in the lumen. There are so many different species that we have a new collective noun for them, the microbiome (or microbiota).
Colonic bacteria are fermenters and assist with the digestion of food. They break down complex polysaccharides like resistant starch, pectins and cellulose that our own enzymes do not tackle. Employing a little chemical wizardry they produce acetic, propionic and butyric acids that are consumed by the cells that line the gut wall. The short chain fatty acids also protect our colonic cells from becoming cancerous.
Our immune system interacts with the bacteria. The gut lining is a barrier to unwelcome invasion that is continually patrolled and defended by immune cells. Our cells are primed, ready for a fight, but most microbes would rather co-exist than initiate a battle. Gut bacteria target immune peace-keepers called T-regulatory cells (Tregs). Short-chain fatty acids produced by fermentation promote the action of Tregs and so help maintain the association.
Commercial interest in this area is developing fast. According to a recent report from MarketsandMarkets, the Human Microbiome Market is expected to reach $658 million by 2023 from $294 million in 2019. Initial activity in the Biotech and Pharmaceutical industries is showing the potential of research in this field. US company, Seres Therapeutics, is starting phase 2 clinical trials of a bacterial spore treatment for recurring Clostridium difficile, a troublesome gastrointestinal pathogen that can be hard to treat. It won’t be long before consumer markets develop new products and claims. We may soon see novel strains of probiotics, or food ingredients with functional benefits for our gut flora.